A parafoil is a fabric structure used in high-performance parachute jumping and some powered paraglider vehicles. A Rogallo wing is a triangular fabric delta-wing that is attached to ridged rods or tubes along the leading-edge, with another ridged rod or tube aligned front-to-back (chord-wise) and attached at the front to the leading-edge rods/tubes. It is advantageous to use a parafoil or Rogallo wing because they are light-weight fabric structures that can be folded up for easy carrying or storage and can be readily deployed when needed. A disadvantage of using these fabric wings is that they have a large wing surface area, causing them to operate at low speeds (below 30 mph for a parafoil and below 50 mph for a Rogallo wing). At higher speeds (i.e., above 60 mph), Rogallo wings and parafoils become unstable and/or difficult to control.
Existing parafoil systems rely on air blowing into openings along the leading-edge to inflate the fabric, thereby creating a wing shape. This inflow of air is the result of forward flight, and the air-speed and angle of incidence must be within a specific range in order for the parafoil to operate properly. Therefore, each parafoil is designed to carry a particular weight and fly at a specified speed. Also, because the wing is entirely made of fabric, if the speed, angle of incidence, or weight are exceeded, the wing can collapse. Conventional parafoils cannot operate at high speeds because the fabric begins to flutter and the wing has too much area and produces too much drag. Similarly, conventional parafoils are unable to operate over a wide range of speeds or be easily adapted to carry different weights.
A need exists for a wing that can carry a payload and operate at high speeds without suffering the aforementioned drawbacks.